Re: [PATCH 0/8] Introduce fwctl subystem

David Ahern
2024-06-06T17:47:22Z

On 6/6/24 9:05 AM, Jakub Kicinski wrote:
> On Thu, 6 Jun 2024 11:48:18 -0300 Jason Gunthorpe wrote:
>>> An argument can be made that given somewhat mixed switchdev experience
>>> we should just stay out of the way and let that happen. But just make
>>> that argument then, instead of pretending the use of this API will be
>>> limited to custom very vendor specific things.
>>
>> Huh?
>
> I'm sorry, David as been working in netdev for a long time.

And I will continue working on Linux networking stack (netdev) while I
also work with the IB S/W stack, fwctl, and any other part of Linux
relevant to my job. I am not going to pick a silo (and should not be
required to).

> I have a tendency to address the person I'm replying to,
> assuming their level of understanding of the problem space.
> Which makes it harder to understand for bystanders.
>
>> At least mlx5 already has a very robust userspace competition to
>> switchdev using RDMA APIs, available in DPDK. This is long since been
>> done and is widely deployed.
>
> Yeah, we had this discussion multiple times

The switchdev / sonic comparison came to mind as well during this
thread. The existence of a kernel way (switchdev) has not stopped sonic
(userspace SDK) from gaining traction. In some cases the SDK is required
for device features that do not have a kernel uapi or vendors refuse to
offer a kernel way, so it is the only option.

The bottom line to me is that these hardline, dogmatic approaches -
resisting the recognition of reality - is only harming users. There is a
middle ground, open source drivers and tools that offer more flexibility.